Movable aircraft turbine blade equipped with blade mass adjustment means and associated aircraft turbine

Abstract

This movable aircraft turbine blade (1) extends between an outer end (2) provided with a blade heel (4) and an inner end (3) provided with a blade mounting foot (5) and an inner platform (6). The blade (1) comprises a blade (7) extending between the inner platform (6) and the blade heel (4). The blade (1) is equipped with mass adjustment means (8) comprising at least one mass mounting hole (9) and one or more masses (10) fixedly mounted in said at least one mass mounting hole (9). Figure for the abbreviation: Figure 1

Description

Title of the invention: Movable aircraft turbine blade equipped with blade mass adjustment means and associated aircraft turbine technical field

[0001] The present invention relates generally to a movable aircraft turbine blade and an associated turbine. More particularly, the invention relates to the balancing of such a blade. Previous techniques

[0002] Due to manufacturing tolerances of parts, it is sometimes necessary to implement balancing of the different parts of an aircraft turbine.

[0003] Indeed, the presence of an imbalance on the turbine would result in the appearance of harmful vibrations and the reduction of operating clearances, which would lead to a reduction in the lifespan of the turbine.

[0004] Thus, to control and limit the level of imbalance, particularly in the low-pressure turbine, balancing is conventionally carried out at the turbine rotor. Typically, balancing weights are fixed to an upstream annular flange of an upstream disc and / or to a downstream annular flange of the downstream disc, by means of bolts.

[0005] From the prior art, it is known, in order to further adjust the balancing or for vibration endurance testing, to equip the moving blades of an already assembled aircraft turbine with either pins or clips. A pin is a metal rod wound around the blade. A clip is an element clipped onto the blade's heel.

[0006] However, the use of such means for balancing already assembled turbines can lead to blade breakage during assembly or operation. Description of the invention

[0007] The invention aims in particular to provide a robust balancing of turbine blades, without risk of degradation of the blades either during assembly or operation.

[0008] The invention relates to a movable aircraft turbine blade extending between an outer end equipped with a blade heel and an inner end equipped with a blade mounting foot and an inner platform. The blade comprises a blade extending between the inner platform and the blade heel.

[0009] The blade is equipped with mass adjustment means comprising at least one mass fixing hole and one or more masses fixedly mounted in said at least one mass fixing hole.

[0010] Thus, the invention advantageously allows the mass of the blade to be adjusted in a simple, robust manner and without risk of degradation of the blade either during assembly or operation.

[0011] Preferably, the mass adjustment means further include means for securing the masses in the mass mounting holes. Such mounting means further increase the reliability of the fastening.

[0012] For example, the fastening means include a threaded sleeve fixedly mounted in an associated mass fastening hole and cooperating with a thread formed on an associated mass.

[0013] Advantageously, the mass adjustment means are arranged in the blade root. This configuration increases the effectiveness of the mass adjustment means for rotational balancing by placing them close to the free end of the blade.

[0014] For example, the mass adjustment means are arranged in a groove of the blade heel.

[0015] Preferably, the mass adjustment means are arranged in a slat located along a downstream edge of the blade heel. Such a configuration reduces drag and consequently increases turbine performance.

[0016] According to one feature, mass adjustment means are arranged in the inner platform.

[0017] According to another aspect, the invention relates to an aircraft turbine equipped with at least one blade as defined above. Brief description of the drawings

[0018] Other objects, features, and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawing, which is a perspective view of a movable blade equipped with mass adjustment means according to one embodiment of the invention. Detailed description of at least one embodiment

[0019] The blade 1 of [Fig.1] is a movable aircraft turbine blade that extends between an outer end 2, located in the vicinity of the free end of the blade, and an inner end 3. The outer end 2 is provided with an outer platform or blade heel 4, the inner end 3 comprising a blade fixing foot 5 and an inner platform 6.

[0020] The blade 1 comprises a blade 7 extending between the inner platform 6 and the blade heel 4.

[0021] The blade 7 connects at its inner radial end to the inner platform 6 on an outer face 6a of the platform which delimits, on the inside, the vein of gas flow in the turbine. At its outer radial end, the blade 7 connects to the blade heel 4 on an inner face 4a which delimits, on the outside, the gas flow channel.

[0022] The blade 1 is equipped with mass adjustment means 8 comprising at least one mass mounting hole 9 and one or more masses 10 fixedly mounted in the mass mounting hole 9. Preferably, the mounting holes 9 are through holes. Alternatively, blind mounting holes 9 may be provided.

[0023] Preferably, the mass adjustment means 8 are located in the blade flange 4. Alternatively, the mass adjustment means 8 may be located in the inner platform 6. In some cases, mass adjustment means 8 may be located in both the flange 4 and the inner platform 6.

[0024] According to the embodiment illustrated in [Fig. 1], the mass 10 is a screw.

[0025] Preferably, the mass adjustment means 8 further include means of fixing 11 the masses 10 in the mass fixing holes 9. Alternatively, the fixing of the masses 10 in the fixing holes is carried out without the use of specific fixing means 11, for example by screwing, by force insertion, by gluing, by snap-fitting or by welding.

[0026] For example, the fastening means 11 include a threaded sleeve. The threaded sleeve is fixedly mounted in a mounting hole 9 of an associated mass and cooperates with a complementary thread formed on an associated mass 10. Preferably, a key connection can be provided between the sleeve and the mounting hole 9, so as to prevent relative rotation between the sleeve and the hole 9.

[0027] Alternatively, the fastening means 11 may be nuts.

[0028] As illustrated in the embodiment shown in [Fig. 1], the heel 4 carries slats 4b along its upstream and downstream edges in the direction F of the gas flow. Preferably, the mass adjustment means 8 are arranged in a slat 4b of the heel 4. Advantageously, the mass adjustment means 8 are arranged in a slat 4b located along the downstream edge of the heel 4, so as to reduce aerodynamic disturbances of the gas flow.

Claims

Demands

1. Movable aircraft turbine blade (1) extending between an outer end (2) provided with a blade heel (4) and an inner end (3) provided with a blade mounting foot (5) and an inner platform (6), said blade (1) comprising a blade (7) extending between said inner platform (6) and said blade heel (4), characterized in that said blade (1) is equipped with mass adjustment means (8) comprising at least one mass mounting hole (9) and one or more masses (10) fixedly mounted in said at least one mass mounting hole (9).

2. Blade (1) according to claim 1, wherein said mass adjustment means (8) further comprise means for fixing said masses (10) in said mass fixing holes (9).

3. Blade (1) according to claim 2, wherein said fastening means (11) comprise a threaded bushing fixedly mounted in a fastening hole (9) of associated mass and cooperating with a thread formed on an associated mass (9).

4. Blade (1) according to any one of claims 1 to 3, wherein said mass adjustment means (8) are disposed in said blade heel (4).

5. Blade (1) according to claim 4, wherein said mass adjustment means (8) are disposed in a slit (4b) of said blade heel (4).

6. Blade (1) according to claim 5, wherein said slit (4b) is disposed along a downstream edge of said blade heel (4).

7. Blade (1) according to any one of claims 1 to 6, wherein mass adjustment means (8) are disposed in the inner platform (6).

8. Aircraft turbine equipped with at least one blade (1) according to any one of claims 1 to 7.

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